Alert archive / South Dakota / Tornado Warnings in 1999

Tornado Warning 12, NWS Aberdeen, SD

July 7, 1999McPherson County, South Dakota

NWS Aberdeen, SD issued this tornado warning at Jul 7, 1999, 11:50 PM CDT for McPherson County, South Dakota. It was in force for 35 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: Jul 7, 1999, 11:50 PM CDT (04:50 UTC)
Expired: Jul 8, 1999, 12:25 AM CDT
In force: 35 min
Issued by: NWS Aberdeen, SD
Area: Whole counties

County McPherson County, SD

The radar

The Aberdeen radar (KABR), 72 km from the middle of the area, began a volume at 04:49 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where	Remark
Jul 8, 12:35 AM CDT	Thunderstorm Wind 61	Eureka, SD	Several trees and numerous tree branches were downed as a result of the high winds. Also some shingles were torn off of the house.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 7, 11:30 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

Aberdeen, SD (KABR), launched 00:00Z, 4.8 hours before the alert went out and 116 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 22 J/kg
Mixed-layer CIN: -361 J/kg
Mixed-layer LCL: 2040 m above ground
0-6 km bulk shear: 47 kt
0-1 km storm-relative helicity: -4 m²/s²
0-3 km storm-relative helicity: 137 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KABR 080451 RRA
TORABR
SDC089-080525-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE ABERDEEN SD
1150 PM CDT WED JUL 7 1999

THE NATIONAL WEATHER SERVICE IN ABERDEEN HAS ISSUED A

* TORNADO WARNING FOR...
  MCPHERSON COUNTY IN NORTHEASTERN SOUTH DAKOTA

* UNTIL 1225 AM CDT

* AT 1149 PM CDT... ABERDEEN DOPPLER RADAR INDICATED A TORNADO 45
  MILES NORTHEAST OF MOBRIDGE OR 3 MILES NORTHEAST OF EUREKA MOVING
  NORTHEAST AT 25 MPH.

* THE TORNADO WILL BE NEAR...
  NORTH OF EUREKA ALONG HIGHWAY 47

GO TO THE BASEMENT OR A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

SK/ECKBERG

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Aberdeen, SD wrote its last area forecast discussion before this tornado warning went out at Jul 7, 9:01 PM CDT, 2 hours 49 minutes earlier.

Area forecast discussion, Jul 7, 9:01 PM CDT, 2 hours 49 minutes before

AREA FORECAST DISCUSSION FOR CENTRAL/NORTHCENTRAL AND NORTHEAST
SOUTH DAKOTA AND WEST CENTRAL MINNESOTA
NATIONAL WEATHER SERVICE ABERDEEN SD
900 PM CDT WED JULY 7 1999

CURRENTLY WATCHING CONVECTION IN WESTERN SOUTH DAKOTA.  CURRENT CAPE
VALUES OF OVER 4K J/KG WITH -8 LIS IN PIR AREA PER LAPS MODEL.  00Z
ABR SOUNDING SHOWS WARM MID LEVEL WITH H7 TEMP OF +11 C.  CURRENT
GOES SOUNDINGS ALSO SHOW WARM MID LEVELS WITH SIMILAR H7 TEMPS.  ETA
SHOWS STRONG WAA ESPECIALLY AT MID LEVEL WHICH SHOULD INHBIT
CONVECTION TRYING TO MOVE INTO OUR CWA.  CURRENT PACKAGE DESCRIBES
SITUATION WELL AND NO CHANGES ARE ANTICIPATED.

.ABR...NONE.
KEEFE

The office that day

Everything else NWS Aberdeen, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 7, 10:08 PM CDT	Severe Thunderstorm Warning	ABR	Corson	32 min
Jul 7, 10:19 PM CDT	Severe Thunderstorm Warning	ABR	Campbell	36 min
Jul 7, 11:19 PM CDT	Severe Thunderstorm Warning	ABR	Campbell, McPherson	31 min
Jul 8, 12:20 AM CDT	Tornado Warning	ABR	Edmunds	30 min
Jul 8, 12:22 AM CDT	Tornado Warning	ABR	Brown	48 min
Jul 8, 12:24 AM CDT	Tornado Warning	ABR	McPherson	36 min
Jul 8, 1:28 AM CDT	Flash Flood Warning	ABR	McPherson	4 hr
Jul 8, 1:46 AM CDT	Severe Thunderstorm Warning	ABR	Brown	64 min
Jul 8, 2:43 AM CDT	Severe Thunderstorm Warning	ABR	Day	62 min

Nearby

Tornado Warnings in South Dakota, 1999 Every tornado warning in 1999 Tornadoes in 1999

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.